1. Field of Invention:
The present invention relates to apparatus for grasping, handling and movement of large diameter pipes and tubing and other tubular members.
2. Description of Prior Art:
Large inner diameter pipes and tubing are coming into increasing use in hydrocarbon drilling and production operations, for example in platform installations and the like. In assembling sections or strings of these large diameter pipe, it is necessary to handle and move them. The problems of gripping and moving large hollow pipes and tubing were considerable. U.S. Pat. No. 3,265,431 is the only patent known to applicants dealing specifically with handling and moving of large diameter tubular members. Due to the size and weight of this type of tubular members, stability and balance of handling of these members was important. For this reason, any minor misalignment between structure in the gripping apparatus for engaging the tubular member and the members could cause handling problems during lifting or other movement. Also, misalignment between the handling structure and the tubular member could cause loading problems.
Other types of prior patents relating to engagement with the interior of tubular structure are set forth in U.S. Pat. Nos. 2,523,972; 2,624,610; 2,468,563; 2,687,324; 2,939,739 and 3,709,546. However, so far as is known, these types of structures have not been used with large diameter tubular members.